COMMUNITY FORUM

Shed circuit

I have a shed about 100' away from the main panel and want to put just a light and one outlet in it. Should I run #10-3 and fuse it to a 20 amp breaker?? Also should I run single conductors in plastic or bury UF underground?? Thanks for a response, EdPSI say a 100' because I have to run from the whole length of the house then out the side and back to where the shed is.

How you run the circuit depends on the kind of flexibility you need for the future and how much work you are willing to do. Taking your question at face value you need only dig a one foot deep trench, run the 10/3 W Ground UF cable, protect it with a Ground Fault Circuit Interrupter (GFCI) in the house, terminate it to a single pole switch just inside the shed that will cut all power to the shed, and run your interior wiring to the light and receptacle from the load side of that switch. You will than have two switches in the shed. The first one will kill all power to the shed. The second will be your light switch. The first switch is located in the box were the UF conductors first enter the shed. That first switch is the building disconnecting means and it is required by the US NEC.

If you want outside lights at both the house and the shed that you can control from either end then you will want four wires plus ground and it may be hard to find UF cable in ten gauge with four insulated conductors. In that case you can bury a PVC conduit under one foot of earth if you protect the circuit with a GFCI. If you bury the conduit under eighteen inches of earth you will not have to provide GFCI protection and you can avoid any possibility of nuisance tripping of the circuit do to moisture in the underground conduit or cable. You would also need to make sure that the conductors serving the outside light never enter the interior of the shed or that there is a switch that will deenergize the entire circuit were it originates in the house. --Tom